Overbed table



Dec. 2 1964 w. H. ARMSTRONG OVERBED TABLE 2 Sheets-Sheet 1 Filed Aug. 28, 1962 Dec. 1964 w. H. ARMSTRONG OVERBED TABLE Filed Aug. 28, 1962 2 Sheets-Sheet 2 0 ligilim AIIIH I/ fnvenz af Zdz'ZZzfam HGT-wire 2% 52mm, 9. m

tates fice 3,162,150 GVEREED TABLE William H. Armstrong, Birmingham, Mich, assignor to Borg-Warner (Ierporation, Chicago, 111., a corporation of Illinois Filed Aug. 28, 1962, Ser. No. 225318 9 Claims. Cl. 108-147) This invention relates to a table and more particularly to a vertically adjustable invalid or overbed table.

It is highly desirable to provide a table that may be positioned over a patient and that may be readily adjusted in the vertical direction to accommodate the patient. In the past, this has been done by providing a table having a base-supported vertically adjustable table top wherein an external crank is provided that may be manipulated by the patient or an attendant to actuate a mechanism for vertically positioning the table top. Although the crank mechanism provides an operable structure for adjusting the table, it also presents an awkward, cumbersome and hazardous arrangement for the patient inasmuch is pivotable into a recess in the table results in a complicated crank and table construction which is also unduly complicated and expensive. Further, the type of crank that is pivotable into a table recess is not readily accessible to the invalid or other person attempting to adjust the table; and inasmuch as an invalid or other patient is quite often physically handicapped or otherwise possessed of limited strength and dexterity, the pivoted type of crank is quite often aggravating or beyond the capabilities of the invalid or patient.

It is, therefore, extremely important to be able to provide an overbed table that is vertically adjustable by a simple fingertip movement of the patient and that provides a structure void of expensive, awkward and cumbersome external devices such as protruding, foldable I or pivotable cranks requiring strength and dexterity to operate.

It is a primary object of this invention to provide an overbed table of relative simple and economical construction that is readily adjustable in the vertical direction.

7 extending upwardly from the member. 13.

Another object of this invention is to provide an overbed table that can be readily adjusted vertically by an invalid or other patient with a simple easy fingertip touch.

A further object of this invention is to provide a vertically adjustable overbed table that provides ready access to'the adjusting mechanism therefor and that is void of any protruding cumbersome or awkward manipulating mechanism such as a crank which would be extremely diflicult or physically impossible for certain invalids or patients to manipulate.

An additional object of this invention is to provide an overbed table that may be adjusted vertically by a touch of the fingertips but which will resist undesirable movement of the table from the adjusted position due to the force of gravity or other external forces exerted on the table itself.

the base and wherein a wheel, adapted for actuating the screw mechanism when rotated, is rotatably mounted in a table top wheel housing and extends through an opening in the housing to provide ready access to the wheel for allowing manual rotation of the wheel to adjustably position the table top.

Other objects, advantages, and novel aspects of the invention will become apparent upon the following detailed description in conjunction with the accompanying drawings wherein:

FIG. '1 is an isometric view of the overbed table showing the overall structure thereof.

FIG. 2 is a partial sectional view taken along line 22 of FIG. 1 showing the internal structure of the overbed table.

FIG. 3 is a partial sectional view taken along line 3-3 of FIG. 2 showing the drive mechanism for adjusting the height of the table.

FIG. 4 is a sectional view taken along line 44 of FIG. 2 showing the telescoping portions of the overbed table and the interconnecting adjusting screw and nut mechanism.

Referring to the drawings, there is illustrated an overbed table structure that embodies applicants invention (FIG. 1) and which is generally designated by the numeral 10. The overbed table v1t) includes generally a base 11 and a top 12. The base 11 includes generally a horizontal base member 13 and a vertical column 14 The base member 13 (FIGS. 1 and 2) is provided with stationary and pivotally mounted pairs of supporting casters 15 and 16, respectively, anopening 14 therethrough, a rectangular column opening 17, and a downwardly opening cavity 13.

The vertical base'column 14 (FIG. 2) is provided with a support arm 2% that welded to the column 14 at 21 and that extends into the cavity 18 in engagement with surfaces 19 of the base 13. The column 14 and the arm 20 are supported in position (FIG. 2) by screws 22 inserted through arm holes 23 and threaded into holes 24 in the base member 13. The column 14 thereby provides a rigid vertical extension of the base member 13 for supporting the table top 12.

The overbed table top 12; includes generally a table platform 30, a wheel housing 31, a wheel assembly 32, a table top column 33, and a table top positioning screw mechanism generally designated by the numeral 34. The wheel housing 31 is provided with a wheel cavity 35, a wheel opening 36 and is secured to the underside of j the table platform 34? by screws 37. The table top column 33 is telescopically positioned on the base column 14 and is welded to the wheel housing 31 at 38. The table top column is telescopically and slidably supported on the base column 14 on curved surfaces 39 of support brackets 44) that are secured to the base column 14 on outer corners 41 of the column 14. The base and table top columns 14 and 33 are interconnected by the adjustable screw mechanism -34.

The screw mechanism 34 includes generally a shaft 45, pinion 46, stationary thrust bearing 47, thrust washer 48,

ball bearing nut 49 and nut anchor bracket 50. The shaft With these and other objects in view, the present invenadjusting the vertical position of the table top member on I 45 is rotatably supported in a vertical passage 51 in the wheel housing 31 by the stationary thrust bearing 47. The

shaft 45 is provided with a ball screw threaded lower portion 52 and the thrust washer 48 is positioned between the ball screw threaded portion 52 and the bearing 47 to .pre-

vent upward axial movement of the shaft 45. The pinion 46 is drivingly secured to the upper end of the shaft 45 with a lower radial surface 53 thereof in engagement with a surface 54 of the wheel housing 31 to prevent downward axial movement of the shaft'45. The shaft 45 is thus held against all axial movement relative to the Wheel housing 31. g

The ball bearing nut 47 is threadedly mounted on the ball screw threaded lower portion 52 of the shaft 45. Although the nut 47 maybe any one of several known types of screw drive nuts, the nut 49 illustrated (FIGS. 2 and 4) is the commercially available type having ball bearings 55 (FIG. 4) confined in a channel 56 with the ball bearings 55 in rolling engagement with ball screw threads 57 of the ball threaded shaft portion 52 of the shaft 45 The use of such a ball bearing nut '49 provides an axial drive relative to shaft 45 in response to rotation of the shaft 45 with minimum frictional resistance.

The ball bearing nut 49 is secured to the upper portion of opposite inner Wall'sur'faces 58 of the base column 14 by the nut anchoring bracket '50. The bracket 5% is provided with an aperture 59 that allows the bracket 5% to be "positioned over a threaded portion 61 of the ball hearing nut 49 against a shoulder 61 of the ball bearing nut 49. The bracket 50 is held in place against the shoulder by a securing nut 62 threaded on the threaded portion 60 of the ball bearing nut 49. The bracket 50 is provided witha pair of securing flanges 63 that are welded orsimilarly secured to the opposite inner walls 518 of the base column 14 at 64 to anchor the ball bearing nut 49 to the base column 14 by virtue of anchoring the bracket 'S O'to thecolumn '14.

The operation of the screw mechanism 34 is such that the table top 12 may be positioned on the base 11 by rotating the shaft 45. In particular, 'the shaft 45 is held against axial movement relative to the wheelhousing 31 by virtue'of the thrust Washer 48 and the pinion 46 and.

the shaft 45 is in threaded driving engagement with the ball bearing nut 49 which is rigidly secured to the lower base column 14 as previously described. Consequently, rotation of the shaft 45 in either direction will cause the shaft '45 to move axially relative to the stationarily held ball bearing nut 49 and, as a result, the table top 12 will likewise be moved to a position determined by the extent and direction of rotation of the shaft 45. Specifically, if the pinion 46 is rotated clockwise (FIG. 3) the shaft :45 will be threaded downwardly through the stationary ball bearing'nut 49 and the table top 12 willbe lowered; and, conversely, if the pinion 46 is rotated counterclockwise, the tabletop 12 will be" raised.

The wheel assembly 32 includes generally a wheel 69, a one-way clutch 71 and a friction device 72. The wheel 69 is rotatably mounted on a screw 73 inserted through an axial opening 74 in the wheel 69 and threaded into an opening 75 in the'wheel housing 31. The wheel 69 is provided with'agea'r 70 and is'positione'd bythe screw 73 so that the gear 70 is in driving engagement with the pinion 46': Further,'the wheel 69 is positioned so that a small peripheral handgrip portion 76 of the wheel 69 extends through the wheel housing opening lie-and is there by readily accessible for manual rotation by the patient "-or other operator.

The one-way clutch 71 is positioned on the screw 73 between the wheel 69and the wheel housing 31 (FIG. 3) 'andinclu'des an inner race 77, secured tot-he wheel 76, an outer race 78 concentric with-the inner'race'77 and inter connecting one-way sprags 79 that are pivotally retained in a cage '80. The sprags 79 are pivotally retained and inclined (FIG. 3) so as to'provide a-driving connection between the inner and outer races 77 and '73 when the inner race 77 is rotated"clockwise and'to provide no driving connection between the inner and outer races 77 and 78 when the inner race 77 is driven counterclockwise.

- The friction device 72 (FIGS, 2 and 3) includes generally a pressure plate 85, a resilient friction O-ring 85 anda pair of adjusting screws 87. The friction O-ring is made ofrubber or similar resilient material and is positioned over the outer race 78 in engagement with a complementary flange 88 on'the base of the outer race 78 ad acent an inner surface89 of theqwheel'housing 31. The

pressure plate is provided with a groove 90 positioned over the O-ring 86 with the O-ring retained within the groove 90 of the pressure plate 85.

The pressure plate 85 is secured to the wheel housing 31 by the pair of friction adjusting screws 87 inserted in openings 91 in the bottom of the wheel housing 31 on opposite sides of the screw 73 and threaded into raised openings 92 (FIG. 3) in the pressure plate 85. The adjusting screws 87 may be rotated to tighten or loosen the pressure plate 85 against the O-ring 86 toward or away from the flange 88 of the outer race 78 and the surface 89 of the wheel housing 31 to increase or decrease the frictional contact between the O-ring 86 and the flange 88 of the outer race 78 to provide a variable frictional drag on the outer race 7 3.

Inasmuch as the one-way clutch 71 operates to connect the outer race 78 with the inner race 77, only when the inner race is rotated in the counterclockwise direction (FIG. 3) and inasmuch as the inner race 77 is secured to the wheel 69, the friction device 72 is only effective on the wheel 69 when the wheel is rotated in the counterclockwise direction. The screw threads 57 and the gears 46 and 70 are so constructed and positioned that the table top 12 will be lowered when the wheel 69 is rotated in the counterclockwise direction and the friction device '72. is operable through the oneway clutch 71 for resisting movement of the wheel 69 that causes the lowering of the table top 12.

The above described friction device is a highly de sir-able feature of the present invention inasmuch as the force of gravity or other load exerted on or by the table top 12 through the positioning mechanism 34 will cause a reaction between the nut 49 and the shaft threads 57 that will be transmitted through the gears 46 and 70 to the wheel 69 to cause the wheel 69 to rotate in the counterclockwise direction and thereby result in a spontaneous lowering of the table top 12. The friction device 72, through the one-way clutch 61, thereby provides a means for resisting such spontaneous lowering of the table 12 and, depending on the adjustment of the adjusting screws 37, can maintain an adequate friction resistance to varying table loads that tend to cause spontaneous movement without positively locking the wheel against movement and without undue resistance to the manual rotation of the wheel in either direction at all times.

Thus, applicants invention provides an overbed table 10 having an adjustable screw mechanism 34 for telescopically positioning a table top 12 on an extended base 11 by manual rotation of a partially exposed wheel '69 otherwise enclosed in a table top wheel housing 31 wherein adjusting rotation of the Wheel 69 is resisted by an adjustable friction device that prevents spontaneous lowering of the table top that results from an external lowering force exerted thereon. Further the table of the illustrated type 10 provides an overbed table that is vertically adjustable by a minimum of fingertip effort and movement and that provides a structure void of expensive, awkward, and cumbersome external devices such as the protruding foldable or pivotal cranks requiring strength and dexterity to manipulate.

I wish it to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

l. A vertically adjustable ovcrbed table comprising a base having a vertical tubular extension, a table top having a vertical tubular extension telescopically movably mounted on said tubular base extension, means 'for' adjustably interconnecting said table top extension rotated, said wheel extending beyond said housing through the housing aperture for providing exterior access to said wheel to allow manual rotation thereof, and means for resisting adjustment of the table other than by movement of said wheel.

2. A vertically adjustable overbed table comprising a base having a vertical tubular extension, a table top having a vertical tubular extension telescopically movably mounted on said tubular base extension, means for adjustably interconnecting said table top extension and said base extension and operable to position said table top extension on said base extension to vertically position said table top relative to said base, a wheel housing forming a part of said table top and having an aperture therein, and a wheel rotatably mounted on said table top within said wheel housing and drivingly connected with said adjustable interconnecting means for operating said adjustable interconnecting means when said wheel is rotated, said Wheel extending beyond said housing through the housing aperture for providing exterior access to the outer periphery of said wheel to allow manual rotation thereof, and means for resisting rotation of said wheel in one direction to resist lowering adjustment of the table top. 1

3. A vertically adjustable overbed table comprising a base having a vertical tubular extension, at table top having a vertical tubular extension telescopically movably mounted on said tubular base extension, means for adjustably interconnecting said table top extension and said base extension and operable to position said table top extension on said base extension to vertically position said table top relative to said base, a wheel housing forming a part of said table top and having an aperture therein, a wheel rotatablymounted on said table top within said wheel housing and drivingly connected with said adjustable interconnecting means for operating said adjustable interconnecting means when said wheel is rotated, said wheel extending beyond said housing through the housing aperture for providing exterior aet cess to said wheel to allow manual rotation thereof, a

friction means secured to said table top and positioned adjacent said wheel, and a one-way clutch in engagement with said wheel and said friction means and operable in one direction of rotation of said wheel for applying said friction means to said wheel to resist lowering adjustment of said table top.

4. A vertically adjustable overbed table comprising a base having a vertical extension, a table top slidably mounted on said base extension, mean for adjustably interconnecting said table top and said base extension and operable to position said table top on said base extension, a wheel housing forming a part of said table top and having an aperture therein, a wheel rotatably mounted on said table top within aid wheel housing and drivingly connected with said adjustable interconnecting means for operating said adjustable interconnecting means s when said wheel is rotated, said wheel extending beyond said housing'through' the housing aperture for providing exterior access tosaid wheel to allow manual rotation thereof, "a one-way clutch rotatably mounted on said wheel housing within said wheel housing, said oneway clutch having an inner drive race drivingly connected to said wheel to bedriven by said wheel, said one-way I clutch having an outer driven race concentricwith said inner race and held against downward axial movement by said wheelh-ousing, a spragca-ge positioned between said inner andsaid outer races, sprags pivotally mounted in 'saidcage for drivingly interconnecting said races to drive said outer race in response to driven rotation of 6 said'inner race when said wh-eelis rotated to adjust said table top downwardly, a radial flange extending outwardly from said outer race and rigidly secured thereto, a resilient axially compressible and nadially exp andible friction ring positioned on said flange in frictional contact with said outer raceand said flange for resisting rotation of said outer race, and a retaining means ad-' justably secured to said wheel housing and positioned on said friction means for axially compressing and radially expanding said friction ring to vary the frictional resistance of said friction means on said outer race.

5. A vertically adjustable overbed table comprising a base having a vertical extension, a table top slidably mounted on said base extension, means for adjustably interconnecting said tabletop and said base extension and operable to position saidtable top on said base extension, a wheel housing forming a part of said table top and having an aperture therein, a wheel rotatably mounted on said table-top within said wheel housing and drivingly connected with said adjustable interconnecting means for operating said adjustable interconnecting means when said wheel is rotated, said Wheel extending beyond said housing through the housing aperture for providing exterior access to said wheel to allow manual rotation thereof, a friction means secured to said table top and positioned adjacent said wheel, and a one-way clutch in engagement with said wheel and said friction means and operable on said wheel in one direction of rotation of said wheel for applying said friction means to said wheel to resist lowering adjustment of said table top.

6. A vertically adjustable overbed table comprising a base having a vertical extension; a table top slidably mounted on said base extension; a wheel housing forming a part of said table top and having an aperture therein; means for adjustably interconnecting said table top and said base extension and operable to position saidtable top on said base extension; said adjustable interconnecting means including a nut secured to said base extension, a threaded shaft rotatably mounted in said wheel housing in threading engagement with said nut, means for retaining said shaft against axial movement relative to said wheel housing for adjustably positioning said wheel housing on said base extension when said shaft is rotatably threaded in said nut, a wheel rotatab'ly mounted on said table top within said housing and extending beyond said wheel housing through the housing aperture for providing exterior access to said wheel to allow manual rotation thereof; gear means drivingly interconnecting said wheel with said shaft for operating said adjustable interconnecting means when said wheel is rotated, and means for resist-ing adjustment of the table other than by movement of said wheel.

7. A verticallyadjustable overbed tab-1e comprising a base having a vertical extension; a table top slidably mounted on said base extension; a wheel housing forming a part of said table top and having an aperture therein; means for adjustably interconnectingsaid table top and said base extension and. operable to position said j table top on said base extension; said adjustable interconnecting means including a nut secured to said base extension, a threaded shaft rotatably mounted in said Wheel housing in threading engagement with said nut, means for retaining said shaft against axial movement relative to said wheel housing for adjustably positioning said wheel housing on said .base extension when said shaft is rotatably threaded in saidnut, a wheel rotatably mounted on said table top within said: housing and vex-- tending beyondsaid wheel housing through the'housing aperture for providing exterior acess to said wheel to allow manual rotation thereof; gear means drivingly ins arena-so base having a vertical extension; a table top slidably mounted on said base extension; a wheel housing forming a part of said table top and having an aperture therein; means fonadjustably interconnecting said table top and said base extension and operable to position said table top on said base extension; said adjustable {interconnecting means including anu-t secured 'to said base extension, a threaded shaft rotatably mounted in said Wheel housing in threading engagement with said nut, means for retaining said shaft against axial movement relative to said Wheel housing for adjustably positioning said wheel housing on said base extension when said shaft is rotatably threaded in said nut, a wheel rotatably mounted on said table top within said housing and extending beyond said whee-l housing through the housingaperture for providing exterior access to said Wheel to allow manual rotation thereof; gear means drivingly interconnecting said wheel with said shaft for operating said adjustable interconnecting means when said Wheel is rotated; a friction element secured to said table top and positioned adjacent said wheel; and a one-way clutch in engagement with said wheel and said friction posit-ion said table top relative to said base; said adjustable interconnecting means including a nut secured to said base extension, a threaded shaft rotatably mounted in said Wheel housing in threading engagement with said nut, means for retaining said shaft against axial movement relative to said wheel housing for adjustably positioning-said wheel housing on said base extension when said shaft is rotatably threaded in said nut, a wheel rotatably mounted on said table top within said housing and extending beyond said wheel housing through the housing aperture for providing exterior access to said wheel to allow manual rotation thereof; gear means drivingly interconnecting .said wheel with said shaft for operating said adjustable interconnecting means when said Wheel is rotated; a friction element secured to said table top and positioned adjacent said wheel; and a oneway clutch in engagement with said Wheel and said friction means and operable in one direction of rotation of said wheel for applying said friction means to said wheel to resist lowering adjustment of said table top.

References Cited in the file of this patent UNITED STATES PATENTS 951,380 Parker Mar. 8, 1910 1,527,895 Mazoch Feb. 24, 1925 11,783,661 'Makos-ki et al. Dec. 2, 1930 2,249,455 Oald-Well July 15, 1941 2,251,841 Herold Aug. 5, 1941 2,368,748 Doty Feb. 6, 1945 2,628,147 'Berner Feb. 10, 1953 3,030,729 'Elden Apr. 24, 1962 

1. A VERTICALLY ADJUSTABLE OVERBED TABLE COMPRISING A BASE HAVING A VERTICAL TUBULAR EXTENSION, A TABLE TOP HAVING A VERTICAL TUBULAR EXTENSION TELESCOPICALLY MOVABLY MOUNTED ON SAID TUBULAR BASE EXTENSION, MEANS FOR ADJUSTABLY INTERCONNECTING SAID TABLE TOP EXTENSION AND SAID BASE EXTENSION AND OPERABLE TO POSITION SAID TABLE TOP EXTENSION ON SAID BASE EXTENSION TO VERTICALLY POSITION SAID TABLE TOP RELATIVE TO SAID BASE, A WHEEL HOUSING FORMING A PART OF SAID TABLE TOP AND HAVING AN APERTURE THEREIN, A WHEEL ROTATABLY MOUNTED ON SAID TABLE TOP WITHIN SAID WHEEL HOUSING AND DRIVINGLY CONNECTED WITH SAID ADJUSTABLE INTERCONNECTING MEANS FOR OPERATING SAID ADJUSTABLE INTERCONNECTING MEANS WHEN SAID WHEEL IS ROTATED, SAID WHEEL EXTENDING BEYOND SAID HOUSING THROUGH THE HOUSING APERTURE FOR PROVIDING EXTERIOR ACCESS TO SAID WHEEL TO ALLOW MANUAL ROTATION THEREOF, AND MEANS FOR RESISTING ADJUSTMENT OF THE TABLE OTHER THAN BY MOVEMENT OF SAID WHEEL. 